Heat-storage medium conveying system for solar-thermal power plant

Abstract

The invention provides a heat-storage medium conveying system for a solar-thermal power plant. The system includes a high-level tank subsystem including a high-level tank used to store the heat-storage medium. The system further includes a heat-storage medium transport subsystem. The high-level tank subsystem is connected with the heat-storage medium transport subsystem. The heat-storage medium transport subsystem includes a low-level tank. A mounting height of the low-level tank is lower than that of the high-level tank. A volume of the low-level tank is smaller than a volume of the high-level tank. The heat-storage medium can enter the low-level tank from the high-level tank partially or completely by its own gravity. The low-level tank is provided with a conveying pump, and the heat-storage medium is pumped out of the low-level tank through the conveying pump. The invention solves the problems such as construction cost, operation and maintenance cost brought about by using the vertical long-shaft submerged molten salt pump, while avoiding the potential safety hazards in the design of large and small tanks or high-level and low-level tanks.

What is claimed is: 
     
       1. A heat-storage-medium conveying system for a solar-thermal power plant, comprising a high-level tank subsystem, the high-level tank subsystem comprising a high-level tank used to store the heat-storage-medium, wherein the system further comprises a heat-storage-medium transport subsystem;
 the high-level tank subsystem is connected with the heat-storage-medium transport subsystem; 
 the heat-storage-medium transport subsystem comprises a low-level tank; a mounting height of the low-level tank is lower than that of the high-level tank; a volume of the low-level tank is smaller than a volume of the high-level tank; the heat-storage-medium may enter the low-level tank from the high-level tank partially or completely by its own gravity; the low-level tank is provided with a conveying pump, and the heat-storage-medium is pumped out of the low-level tank through the conveying pump; and 
 wherein the heat-storage-medium transport subsystem further comprises an uninterrupted compressed gas source; 
 the uninterrupted compressed gas source is communicated with a gas-phase space of the low-level tank through a gas source pipeline, and the gas source pipeline forms a first pipe path; 
 the uninterrupted compressed gas source increases a gas pressure in the low-level tank to decrease a liquid level of the heat-storage-medium in the low-level tank by inflating the low-level tank. 
 
     
     
       2. The system according to  claim 1 , wherein the heat-storage-medium transport subsystem further comprises a first valve assembly;
 the first valve assembly is used to adjust an inflation volume provided by the uninterrupted compressed gas source for the low-level tank; 
 the first valve assembly is disposed on the first pipe path. 
 
     
     
       3. The system according to  claim 2 , wherein
 the first valve assembly comprises two valve groups connected in parallel; each of the valve groups comprises three valves connected in series, i.e., two check valves and an intake adjustment valve disposed between the two check valves. 
 
     
     
       4. The system according to  claim 2 , wherein the heat-storage-medium transport subsystem further comprises a second valve assembly;
 the second valve assembly elevates the liquid level of the heat-storage-medium in the low-level tank by reducing the gas pressure in the low-level tank; 
 the low-level tank is provided with a first gas exhaust pipeline, and the first gas exhaust pipeline forms a second pipe path; 
 the second valve assembly is disposed on the second pipe path. 
 
     
     
       5. The system according to  claim 4 , wherein
 the second valve assembly comprises two valve groups connected in parallel; each of the valve groups comprises two valves connected in series, i.e., an exhaust adjustment valve and a check valve. 
 
     
     
       6. The system according to  claim 1 , wherein the heat-storage-medium transport subsystem further comprises a low-level tank liquid level sensor;
 the low-level tank liquid level sensor is mounted on the low-level tank for detecting the liquid level of the heat-storage-medium in the low-level tank. 
 
     
     
       7. The system according to  claim 1 , wherein the heat-storage-medium transport subsystem further comprises a high-low-level tank isolation valve;
 a first pipeline is disposed between the high-level tank and the low-level tank, the high-level tank is connected with the low-level tank through the first pipeline, and the first pipeline therebetween forms a third pipe path; the high-low-level tank isolation valve is disposed on the third pipe path. 
 
     
     
       8. The system according to  claim 1 , wherein the heat-storage-medium transport subsystem further comprises a temperature regulator;
 the uninterrupted compressed gas source is connected with an inlet of the temperature regulator through a pipeline, and the pipeline connecting therebetween forms a fourth pipe path. 
 
     
     
       9. The system according to  claim 8 , wherein the heat-storage-medium transport subsystem further comprises a heater; the heater is located on the fourth pipe path. 
     
     
       10. The system according to  claim 8 , wherein the heat-storage-medium transport subsystem further comprises a gas pressure adjustment valve;
 an outlet of the temperature regulator is connected with a second gas exhaust pipeline, and the gas pressure adjustment valve is disposed on the second gas exhaust pipeline. 
 
     
     
       11. The system according to  claim 8 , wherein the heat-storage-medium transport subsystem further comprises a temperature sensor; the temperature sensor is mounted on the temperature regulator. 
     
     
       12. The system according to  claim 7 , wherein
 the heat-storage-medium transport subsystem further comprises a flexible connector; 
 the flexible connector is disposed on the third pipe path, and located between the low-level tank and the high-low-level tank isolation valve. 
 
     
     
       13. The system according to  claim 8 , wherein
 the heat-storage-medium transport subsystem further comprises a fourth valve assembly; 
 the fourth valve assembly is used to adjust a volume and a flow rate of a gas entering the temperature regulator; 
 the fourth valve assembly is disposed on the fourth pipe path. 
 
     
     
       14. The system according to  claim 13 , wherein
 the fourth valve assembly comprises an adjustment valve and a check valve. 
 
     
     
       15. The system according to  claim 4 , wherein
 the heat-storage-medium transport subsystem further comprises a third valve assembly; 
 when the first pipe path and the second pipe path share part of the pipeline, the third valve assembly is disposed on the shared pipeline. 
 
     
     
       16. The system according to  claim 1 , wherein the heat-storage-medium transport subsystem further comprises a conveying pump outlet recirculation valve, wherein
 a second pipeline is disposed between the high-level tank and the low-level tank; one end of the second pipeline is connected with an inlet of the high-level tank, and the other end of the second pipeline is connected with an outlet of the conveying pump; the second pipeline forms a fifth pipe path, and the heat-storage-medium may be pumped into the high-level tank from the low-level tank along the fifth pipe path; the conveying pump outlet recirculation valve is disposed on the fifth pipe path. 
 
     
     
       17. The system according to  claim 1 , wherein the heat-storage-medium transport subsystem further comprises a second valve assembly;
 the second valve assembly elevates the liquid level of the heat-storage-medium in the low-level tank by reducing the gas pressure in the low-level tank; 
 the low-level tank is provided with a first gas exhaust pipeline, and the first gas exhaust pipeline forms a second pipe path; 
 the second valve assembly is disposed on the second pipe path. 
 
     
     
       18. A heat-storage-medium conveying system for a solar-thermal power plant, comprising a high-level tank subsystem, a heat-storage-medium heat absorption subsystem and a heat-storage-medium heat exchange subsystem;
 the high-level tank subsystem comprises a high-temperature heat-storage-medium high-level tank used to store a high-temperature heat-storage-medium and/or a low-temperature heat-storage-medium high-level tank used to store a low-temperature heat-storage-medium; wherein the system further comprises a heat-storage-medium transport subsystem, and the heat-storage-medium transport subsystem comprises a high-temperature heat-storage-medium transport subsystem and/or a low-temperature heat-storage-medium transport subsystem; 
 the high-level tank subsystem is connected with the heat-storage-medium transport subsystem; 
 the high-temperature heat-storage-medium transport subsystem is disposed corresponding to the high-temperature heat-storage-medium high-level tank; the high-temperature heat-storage-medium transport subsystem comprises a high-temperature heat-storage-medium low-level tank; 
 a mounting height of the high-temperature heat-storage-medium low-level tank is lower than that of the high-temperature heat-storage-medium high-level tank; a volume of the high-temperature heat-storage-medium low-level tank is smaller than a volume of the high-temperature heat-storage-medium high-level tank; the high-temperature heat-storage-medium may enter the high-temperature heat-storage-medium low-level tank from the high-temperature heat-storage-medium high-level tank partially or completely by its own gravity; 
 the high-temperature heat-storage-medium low-level tank is provided with a high-temperature heat-storage-medium conveying pump; an outlet of the high-temperature heat-storage-medium conveying pump is connected with the heat-storage-medium heat exchange subsystem and the high-temperature heat-storage-medium high-level tank respectively; the high-temperature heat-storage-medium is pumped into the heat-storage-medium heat exchange subsystem from the high-temperature heat-storage-medium low-level tank; 
 the low-temperature heat-storage-medium transport subsystem is disposed corresponding to the low-temperature heat-storage-medium high-level tank; the low-temperature heat-storage-medium transport subsystem comprises a low-temperature heat-storage-medium low-level tank; a mounting height of the low-temperature heat-storage-medium low-level tank is lower than that of the low-temperature heat-storage-medium high-level tank; a volume of the low-temperature heat-storage-medium low-level tank is smaller than a volume of the low-temperature heat-storage-medium high-level tank; the low-temperature heat-storage-medium may enter the low-temperature heat-storage-medium low-level tank from the low-temperature heat-storage-medium high-level tank partially or completely by its own gravity; 
 the low-temperature heat-storage-medium low-level tank is provided with a low-temperature heat-storage-medium conveying pump, and an outlet of the low-temperature heat-storage-medium conveying pump is connected with the heat-storage-medium heat absorption subsystem and the low-temperature heat-storage-medium high-level tank respectively; the low-temperature heat-storage-medium is pumped into the heat-storage-medium heat absorption subsystem from the low-temperature heat-storage medium low-level tank.